The Sokkia DT550 Digital Theodolite delivers 5-second angular accuracy in a compact, field-hardened package built for survey crews, contractors, and alignment technicians who need reliable horizontal and vertical angle measurement across demanding site conditions. With an IP66-rated dust and water-resistant housing, dual-face display, and intuitive controls, the DT550 keeps production moving whether you're setting property corners, squaring building foundations, or running utility corridor alignments.
Overview & Jobsite Applications
The DT550 is engineered for professionals who require consistent, repeatable angle readings without the complexity or cost of a full total station. Its 30x magnification telescope and optical plummet make it equally at home on a residential survey crew, a commercial construction site, or an industrial alignment project. The instrument's lightweight body reduces tripod fatigue on long days while the rugged magnesium alloy frame withstands the knocks of daily transport and use.
Key Specifications
- Angular Accuracy: 5 seconds (5")
- Telescope Magnification: 30x
- Minimum Focus Distance: 1.0 m (3.3 ft)
- Field of View: 1°30' (1.5°)
- Display: Dual-face LCD with backlight
- Angle Reading: Absolute encoder, 1" resolution display
- Compensator: Single-axis liquid tilt sensor
- Plummet: Optical plummet built into alidade
- Dust & Water Resistance: IP66
- Battery Life: Approx. 50 hours (alkaline AA)
- Operating Temperature: -20°C to +50°C (-4°F to +122°F)
- Weight: Approx. 4.4 kg (9.7 lbs) with tribrach
Key Features
- Dual-Face LCD Display: Read angles from either side of the instrument — no repositioning required when working in tight or obstructed setups
- Backlit Display: Maintains readability in low-light conditions, early morning starts, or shaded interior work
- Absolute Encoder: Retains angle settings after power loss — no re-initialization required when the instrument is powered back on
- IP66 Protection: Sealed against dust ingress and high-pressure water jets, suitable for rain-exposed outdoor use
- Optical Plummet: Fast, precise instrument centering over control points without laser drift concerns in bright sunlight
- Standard AA Batteries: Up to 50 hours of operation from readily available alkaline cells — no proprietary battery packs required in the field
- Horizontal & Vertical Hold Buttons: Lock angle readings instantly for transfer measurements and layout reference
Job Applications
Property Line Surveys: The 5-second accuracy meets requirements for boundary surveys, lot splits, and easement determinations where angular precision directly affects legal descriptions and recorded plat accuracy.
Building Foundation Layout: Set and verify 90-degree building corners, column grid lines, and offset control lines with confidence — essential for structural concrete, masonry, and steel framing trades.
Slope & Grade Verification: Use vertical angle readings to calculate grades for drainage swales, road subgrade, and utility trenching where slope tolerances are tightly specified.
Industrial & Utility Alignment: Align pipeline runs, conveyor systems, and transmission tower bases where horizontal angular control over long distances is critical to installation tolerances.
Compatible Accessories
- Sokkia Tribrach with Optical Plummet
- Aluminum Tripod — Heavy-Duty Survey Grade
- Prism Pole with Circular Level
- Sokkia Carrying Case for DT Series
- AA Battery Pack (Field Spare Kit)
Related Guides
- How to Set Up and Level a Digital Theodolite
- Theodolite vs. Total Station: Choosing the Right Instrument for Your Project
- Building Layout Basics: Setting Square Corners with a Theodolite
- Understanding Angular Accuracy in Survey Instruments
Frequently Asked Questions
- Does the Sokkia DT550 measure distances?
- No. The DT550 is a pure digital theodolite designed for angle measurement only — horizontal and vertical. It does not include an EDM (electronic distance measurement) module. For combined angle and distance measurement, consider a Sokkia total station.
- What batteries does the DT550 use, and how long do they last?
- The DT550 runs on standard AA alkaline batteries and delivers approximately 50 hours of operation per set. AA batteries are universally available, eliminating the need to carry proprietary chargers or spare packs in the field.
- Is the DT550 suitable for use in rain?
- Yes. The instrument carries an IP66 rating, meaning it is fully protected against dust and resistant to high-pressure water jets. It is designed for use in typical outdoor weather conditions including rain, though it should not be submerged.
- What is the difference between the DT550 and a total station?
- A theodolite like the DT550 measures horizontal and vertical angles only. A total station adds integrated EDM for slope and horizontal distance measurement, as well as onboard data collection. The DT550 is a cost-effective choice when angle-only work is required or when used alongside a separate EDM or tape measure.
Frequently Asked Questions
Does the Sokkia DT550 measure distances?
No. The DT550 is a pure digital theodolite designed for angle measurement only — horizontal and vertical. It does not include an EDM (electronic distance measurement) module. For combined angle and distance measurement, consider a Sokkia total station.
What batteries does the DT550 use, and how long do they last?
The DT550 runs on standard AA alkaline batteries and delivers approximately 50 hours of operation per set. AA batteries are universally available, eliminating the need to carry proprietary chargers or spare packs in the field.
Is the DT550 suitable for use in rain?
Yes. The instrument carries an IP66 rating, meaning it is fully protected against dust and resistant to high-pressure water jets. It is designed for use in typical outdoor weather conditions including rain, though it should not be submerged.
What is the difference between the DT550 and a total station?
A theodolite like the DT550 measures horizontal and vertical angles only. A total station adds integrated EDM for slope and horizontal distance measurement, as well as onboard data collection. The DT550 is a cost-effective choice when angle-only work is required or when used alongside a separate EDM or tape measure.
